"I have little doubt that the decline in numbers in the wild will continue," said Williams, whose base is the Wildlife Conservation Research Unit at Oxford University in Britain.

"In Ethiopia, I would be pleasantly surprised if there still were Grevy's zebras in, say, 15 years' time," he told IRIN on Monday.

Williams said that lessons could be learnt from the zebra - which is a third bigger than ordinary zebras - because it manages to survive droughts while domestic animals die.

"Grevy's zebras are a metaphor for what is happening to the arid and semi-arid areas and for what management steps need to be taken to remedy the situation," he added.

"Their decline over their range is symptomatic of the degradation of the rangelands which they share with pastoral people and their domestic livestock," he said.

Williams argues that if the Grevy disappears, the nomadic communities living in the remotest parts of the country will become more dependent on western food aid.

"If they are extirpated (lost) from Ethiopia, it would be indicative of a serious collapse in the environment in the areas in which they live," he pointed out. "This would affect the pastoral people because their domestic livestock are dependent on the same environmental conditions as the zebras."

"The management steps to protect the Grevy will benefit the zebra, as well as the pastoral people, their livestock, and the fauna and flora of an area that is more fragile and less resilient than people previously thought," he said.

Grevy's zebras are now listed on CITES (Convention for International Trade in Endangered Species) which means that trade in their skins is not allowed.